How long do you keep chicken/beef stock/broth after opening?I always have more than I need and refrigerate the rest. It ends up in the back of the fridge where I forget about it. Sometime much later, I see it, smell it and, even though it smells fine, I through it away.

I pour leftover stock/broth into ice cube trays, freeze it, and store the cubes in the freezer in plastic bags. It's very convenient when you have a recipe that calls for a small amount of stock--just take out a cube and melt it.

You can keep stock in the fridge, but you have to take it out and boil it every few days to prevent bacteria and molds from growing in it.

Erring on the side of safety, since even one hospitalization or death is too many, the U.S. Department of Agriculture's Food Safety and Inspection Service likes to see us use cooked food or move it on to the freezer within two or three days. That's certainly conservative, but I'd be wary of following Carl's advice, even if it has worked for him.

Tom Troiano wrote:I figure if you're going to remove the fat and boil it (to make soup or a reduction sauce) that the boiling is going kill anything bad. No?

I would think so, Tom, assuming - as you say - careful handling. For the record, a few bacteria are resistant to boiling temps, and some of them are scary. But they are also very, very rare. For commercial use, they can't take that minimal chance. Most of us probably figure "that which doesn't kill us will make us strong."

But the rare exception can be bad stuff, and the decision to risk it is one that only you can make.

Did you click and read the McGee article in my post, Tom? Here's a relevant passage:

Harold McGee wrote:Boiling does kill any bacteria active at the time, including E. coli and salmonella. But a number of survivalist species of bacteria are able to form inactive seedlike spores. These dormant spores are commonly found in farmland soils, in dust, on animals and field-grown vegetables and grains. And the spores can survive boiling temperatures.

After a food is cooked and its temperature drops below 130 degrees, these spores germinate and begin to grow, multiply and produce toxins. One such spore-forming bacterium is Clostridium botulinum, which can grow in the oxygen-poor depths of a stockpot, and whose neurotoxin causes botulism.

Tom Troiano wrote:I figure if you're going to remove the fat and boil it (to make soup or a reduction sauce) that the boiling is going kill anything bad. No?

The layer of fat on top provides a seal to keep oxygen out of the broth. If you move the broth directly from stove to fridge after making it, it's likely to be close to sterile, and to stay that way as long as you don't disturb the layer of fat. My worry would be that there still could be spores of Clostridium botulinum in the broth, and since it's now oxygen-free there's a danger of the bacteria infecting the broth. Boiling the stock later will kill the bacteria but it won't destroy the toxin, so there's a risk of botulism here. I don't think most stocks and broths are acidic enough to be safe from the threat of botulism.

The traditional way to handle long term storage of stock is to store it in the fridge but take it out and bring it to a boil every few days.

Paul Winalski wrote:You can keep stock in the fridge, but you have to take it out and boil it every few days to prevent bacteria and molds from growing in it.

Boiling might kill most of the harmful bacteria, but if the stock is not cooled properly, you run a high risk of it being a breeding ground for more harmful bacteria. Most people do not cool liquid items properly (very rapidly in an ice bath to avoid prolonged temperatures in the "danger zone" - 40-140 deg F). Each time you boil, you expose the stock to the danger zone, so more bacteria grows.

Best rule of thumb - if you aren't going to use it within a week, freeze it.

I use the freeze-in-ice-cube-tray method, too. Assuming you're referring to packaged broth/stock, I just recently found these 8.25 ounce containers. The smaller size is handy. I can't tell you how many times I've discarded leftover stock after forgetting to freeze it.

Just to pile on here, stock is so close to culture broth used in labs to grow bacteria, yeast and even mammalian cells that it must be carefully handled to avoid contamination. Boiling will kill all bacteria; spores are a different matter but rarely an issue in stock making. Another problem is that certain bacterial pathogens such as C. botulinum and E. coli secrete exotoxins that may be resistant to heating.

Freshly prepared stock with a fat layer on top should be good in the fridge for a week or two. Since the most common bacterial contaminants are spoilage bacteria that produce a noticeable odor, a smell test is very useful for determining when is too long. I freeze mine after preparation and only defrost on demand. Sometimes, I'll leave a quart in the fridge for immediate use.